Cruise Control Problem??
 

I have never been fan of MB cruise control since it does not seem to work on about 90% of the MB's from the 80's. On my 1980 wagon the cruise does not engage when you lift the actuator lever, however when you hold and maintain the lever up the car accelerates, right up until you let the lever go, then it disengages. My question is: what went bad? Does this mean that my cruise control amp is no good, actuator or control switch? Or could it be still something else? Thanks a million in advance.

Sounds like the classic symptom for cruise control amplifier failure to me.

Yep, the SDL has started to do the exact same thing. Time to find another cruise control amp, or have these guys rebuild it:

http://www.gdl-online.com/begin.html

BTW, the replacement cruise control didn't work at all. :mad:

My CD started doing that. ANd sure nuff it was the amp.

Probably amp failure. Could also be actuator failure though the symptoms are typically no actuation at all. I have a spare actuator I can sell you if you need.

Where is the cruise amp? Is it the unit that is slightly below the acctuator on the RHS inner fender?

I would suggest S-canning the entire OEM cruise control system and retrofitting an aftermarket version if you want to have a reliable system. There's a few threads about making a conversion if you can find them, the threads that is.

It might be there if you had an Oldsmobile. ;)

Ok, my 240d has pretty much the same problem, the cruise will "kick in" when you hold the set/accel, but as soon as you release it quits. I "resoldered" the amp and now it doesn't work at all.

Does anyone have a schematic to help me debug the connections/switches? I don't have another amp to try, so I want to make sure that it is the problem before I shell out the $$$ for another one.

Thanks.

cruise problem
 

mine hunts on a slight down grade at some speeds.
everything else works fine! with the cruise I mean!
could this be the amp?

why the surging when cruise ctrl engaged?
 

rather than start a new thread i figured i'd ask my question here:

when my cruise control is engaged [87 300E] the car seems to do this surging routine. it manages to maintain the desired speed more or less, but the tach keeps jumpin'. what could this be??
thanks. :)

oh yeah, and how does one gain access to the cruise ctrl amp?